These brightly colored, beautiful creatures look as if someone carefully designed their markings. There are thousands of sea slug species known in the world, and many likely remain undiscovered. Each sea slug has both male and female reproductive organs and releases eggs into the water in clusters, which can contain thousands of eggs.

Sea slugs consume plankton and decaying matter on the ocean floor and algae on rocks and coral reefs. Because they essentially clean the ocean waters, sea slugs are an important part of the marine environment.

The fact that they remain motionless much of the time makes the animals easy prey for lobsters, crabs and other sea creatures. Sea slugs are often caught by humans for food, and also for traditional medicine in eastern cultures, some of which believe that they have healing properties.